Messages in this thread Patch in this message | | | Date | Thu, 15 Mar 2012 14:53:32 -0700 | From | tip-bot for Sasha Levin <> | Subject | [tip:timers/core] ntp: Fix integer overflow when setting time |
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Commit-ID: a078c6d0e6288fad6d83fb6d5edd91ddb7b6ab33 Gitweb: http://git.kernel.org/tip/a078c6d0e6288fad6d83fb6d5edd91ddb7b6ab33 Author: Sasha Levin <levinsasha928@gmail.com> AuthorDate: Thu, 15 Mar 2012 12:36:14 -0400 Committer: Thomas Gleixner <tglx@linutronix.de> CommitDate: Thu, 15 Mar 2012 21:41:34 +0100
ntp: Fix integer overflow when setting time
'long secs' is passed as divisor to div_s64, which accepts a 32bit divisor. On 64bit machines that value is trimmed back from 8 bytes back to 4, causing a divide by zero when the number is bigger than (1 << 32) - 1 and all 32 lower bits are 0.
Use div64_long() instead.
Signed-off-by: Sasha Levin <levinsasha928@gmail.com> Cc: johnstul@us.ibm.com Link: http://lkml.kernel.org/r/1331829374-31543-2-git-send-email-levinsasha928@gmail.com Cc: stable@vger.kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- kernel/time/ntp.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index 17fb1b9..6e039b1 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -289,7 +289,7 @@ static inline s64 ntp_update_offset_fll(s64 offset64, long secs) time_status |= STA_MODE; - return div_s64(offset64 << (NTP_SCALE_SHIFT - SHIFT_FLL), secs); + return div64_long(offset64 << (NTP_SCALE_SHIFT - SHIFT_FLL), secs); } static void ntp_update_offset(long offset)
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